In recent years, an amount of information which an individual can deal with has been significantly measured due to a remarkable advance of digital technology. In connection with this, development of display as information output means has been performed actively, so that technological innovation for displays of high usabilities, such as high definition, low power consumption, light weight, thin shape, etc., has been continued. Particularly, in recent times, a high-definition display which is easy to read and has a display quality equivalent to printed matter has been desired. The display of this type is a technique indispensable to a next-generation product, such as electronic paper, electronic book, etc.
Incidentally, as a candidate for such displays, Evans et al. have proposed an electrophoretic display apparatus in which a dispersion medium containing colored charged electrophoretic (migration) particles and a coloring agent is disposed between a pair of substrates and an image with a contrast color between the colored charged migration particles and the colored dispersion medium is formed, in U.S. Pat. No. 3,612,758.
In such an electrophoretic display apparatus, however, there has arisen a problem such that a life of the display apparatus and a contrast are lowered due to inclusion of the coloring agent such as a dye. In view of these problems, such electrophoretic display apparatuses that an image with a contrast color between colored charged migration particles dispersed in a transparent dispersion medium and a coloring layer disposed on a substrate is formed without coloring the dispersion medium have been proposed in Japanese Laid-Open Patent Applications (JP-A) No. Hei 11-202804 and Hei 09-211499.
Incidentally, in such conventional electrophoretic display apparatuses, the migration particles are moved by an electric field, so that a DC voltage is applied to a display device at the time of display rewriting. However, when such display rewriting is repeated many times, the DC voltage is consequently applied to the display device for a long time in some cases.
Further, when the DC voltage is applied to the display device for a long time as described above, a spatial electric charge distribution is created in an insulating layer or a dispersion medium by electrons, ions, etc., and is accumulated as a residual DC component. As a result, the voltage applied to the migration particles fluctuates, so that there arises such a problem of display burn-in that a predetermined gradation optical level cannot be obtained.